These Giant Cars Solve A Weird Problem For This Tiny Australian Town

Most vehicles on the road today are multipurpose devices. Your four-door truck can do the school run and haul lumber, while your SUV can tow a camper or take you touring off-road. In contrast, jinkers are single-purpose. These Australian oddities are built to do one thing and do it well. You’ll only find them in one place on Earth.

The jinker is an ungainly thing at first glance. They look like a regular vehicle on stilts. Indeed, that is precisely the idea.

The creation of the jinker was all down to the peculiarity of the Gulf of St Vincent, and some good old-fashioned Australian ingenuity. Let’s take a look at these unique, hand-built machines, and learn just how they make life easier on this remote stretch of Aussie coast.

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It’s A Long Way To The Slop

The jinker is primarily found in just two locations along the South Australian coastline. Port Parham claims the jinker as a local invention, but they’ve also been spotted up north at Port Germain. Both towns share something in common—an incredibly flat sea floor paired with six-foot tidal swings. I happened across the town of Parham many years ago when I was arranging a robot mission, and I was floored by the uniqueness of the landscape.

Head out to the beach at Port Parham, and you’ll be struck by just how weird the geography really is. At high tide, the water’s right there with you. Come back at low tide, step out on the sand, and you won’t reach the ocean for a full mile. The seabed is so flat that you can walk for 20 minutes without hitting the water. You’ll tread in just a few puddles left behind from the high tide.

It’s a truly strange landscape—and one that makes launching boats a real pain. There’s no way to build a traditional boat ramp because the sea floor doesn’t drop away fast enough. Even if you did launch your boat on the water at high tide, you’d be screwed when you came back later. Why? Because at low tide, the edge of the water is a full mile further away. You’d either have to time your entrance and exit from the water perfectly with the high tide, or you’d be screwed. With high tides around 12 hours apart, it’s not really practical.

The jinker was the solution to this thorny problem. It’s a vehicle specifically designed for launching boats on this weird bit of coastline. Jinkers are designed for towing boats into the water and nothing else. They keep the engine high and dry, and the driver to boot. These are homebuilt contraptions, of which less than 100 have likely ever been built.

Launching a boat with a jinker is much easier than using a boat ramp. A jinker driver might leave their home a few hundred yards from the shore, towing their boat on a trailer. They’ll head out into the water at a depth of around 3 feet or so, as the tide is coming in. They’ll park the jinker, launch the boat from the trailer on the back, and go fishing. They’ll then come back to the same point around five or six hours later, catching the tide at roughly the same depth on the way out. They can park their boat right on the trailer and then drive the jinker back home.

Jinkers launching boats during high tide at Port Parham.

Jinkers perform their role with surprising mechanical simplicity. They typically run straight-sixes from Aussie cars, most relying on old Holdens and Hemi engines. Drive is sent via the transmission and a horizontal driveshaft to a vertically-mounted differential, which is locked to act as a 90-degree angle drive. This differential then sends power down to a second live-axle diff at the bottom of the jinker, which runs the rear wheels.

This two-differential design has two benefits. Firstly, it neatly transfers drive from the high-mount engine to the low-mounted rear wheels. Secondly, it provides an additional gear reduction which gives the jinker more torque at the wheels.

Relying on old carby engines keeps the jinkers simple. Small fuel tanks made out of jerry cans are typical. Radiator fans are usually fitted as jinkers run quite slowly. Most jinkers have minimal electronics—just enough to run the starter motor and ignition system, and maybe a gauge or two for keeping an eye on vital temperatures. Both automatic and manual gearboxes have been used on jinkers, though there’s not really much call for shifting into high gear. Jinkers are low-speed craft that rely on torque to tow their loads.

Nifty engineering solutions abound on these vehicles. Several jinkers use disc brakes mounted high on the 90-degree differential instead of on the wheels directly. This keeps the disc brake components out of the water, greatly reducing corrosion and thus the amount of maintenance required. Each jinker also has its own unique way of hooking up the steering wheel to the front wheels. I saw one using a full-sized tail shaft in this role.

Many of the jinkers have tow balls mounted front and rear for more flexibility. Meanwhile, suspension is usually limited to a set of springs on the front wheels, if present at all. It’s simply not necessary when running on the soft sand at low speeds.

Better Than The Rest

Jinkers do their job far better than a traditional four-wheel-drive could. Most capable off-road trucks and SUVs would be sucking down water in the kinds of depths jinkers happily operate in. Even if you had a proper snorkel set up, you’d still end up flooding the cabin with seawater most of the time. And your differential. And your battery. Regular off-roaders simply aren’t designed to stay submerged; they’re built for fording a small stream at best.

It’s also one thing to drive out into a few feet of water, and another thing entirely to leave your vehicle sitting in it all day. A typical off-roader would end up hydrolocked or simply drift away as the tide came in further. Jinkers are designed to sit high enough that they can be parked in the water with no risk. Even at high tide, the sea level never reaches the engine. Plus, their open steel frames don’t displace much water, so jinkers don’t float.

Being single-purpose vehicles, jinkers are typically registered as “restricted miscellaneous vehicles” in South Australia. This is a category for vehicles like golf buggies or ATVs which may occasionally need to use public roads. It allows the jinkers to be driven from an owner’s house to the seabed and back again as needed. It’s also more affordable than registering a road-going vehicle to do the same job.

You could never hope to buy a jinker from a large company. The population of Port Parham and Port Germain combined is under 500 people. The market simply isn’t there.

Instead, the jinkers are a great example of local builders engineering vehicles to suit their own needs. They’re highly specialized, highly unique, and highly cool. And, you know, just high in general! Which is kind of the whole point.

I was thoroughly thrilled to see them out on the sand. The town doesn’t have its own tourism bureau, but the local Port Parham Sports and Social Club will gladly sell you a beer and tell you all about these Galapagos Tortoises of the automotive realm. I can confirm it’s well worth dropping in if you find yourself in the area!

Image credits: Lewin Day
Special thanks to Laurence Rogers for IDing the engines on these wonderous craft.